Heat Generation and Degradation Mechanism of Lithium-Ion Batteries during High-Temperature Aging

Abstract

High-temperature aging has a serious impact on the safety and performance of lithium-ion batteries. This work comprehensively investigates the evolution of heat generation characteristics upon discharging and electrochemical performance and the degradation mechanism during high-temperature aging. Post-mortem characterization analysis revealed that lithium plating is the main degradation mechanism. The occurrence of side reactions leads to cell capacity fading and electrochemical performance degradation. The DC resistance and AC impedance increase significantly, and the severe internal polarization makes the incremental capacity curve shift to lower voltage. In the early aging stage, the cell degrades slightly, and the temperature rise rate has not changed significantly upon discharging. The cell capacity plays a leading role, whose degradation makes the temperature rise decrease. With the aging deepening, the severe cell degradation makes the temperature rise rate increase significantly. Even if the capacity fading, the temperature rise still increases significantly compared to the fresh state. Furthermore, irreversible heat and reversible heat increase significantly with the aging deepening and current rate increasing.

Li-Ion Battery Thermal Characterization for Thermal Management Design

“…Heat generation rates change with cell aging, leading to a decrease in capacity and an increase in resistance [20]. However, there is currently a lack of publicly available experimental quantification regarding the effect of aging on battery heat generation.…”

Glycerol Triacetate-Based Flame Retardant High-Temperature Electrolyte for the Lithium-Ion Battery

“…At higher temperatures, conventional low boiling point electrolytes evaporate and decompose, creating a locally dry electrode area with a high resistance. This dry electrode area leads to uneven current distribution and further uneven lithium plating . The surface layer at the anode and the cathode will also decompose at elevated temperatures, especially the organic components. − The exposure of the fresh cathode/anode surface will drive the further reaction of the electrolyte with the electrode and create a thicker SEI/CEI layer, exaggerating the consumption of the electrolyte. , Moreover, cathode active materials will also play an important role in capacity decay at higher temperatures.…”

“…This dry electrode area leads to uneven current distribution and further uneven lithium plating. 16 The surface layer at the anode and the cathode will also decompose at elevated temperatures, especially the organic components. 17 − 19 The exposure of the fresh cathode/anode surface will drive the further reaction of the electrolyte with the electrode and create a thicker SEI/CEI layer, exaggerating the consumption of the electrolyte.…”

Engineering A Boron‐Rich Interphase with Nonflammable Electrolyte toward Stable Li||NCM811 Cells Under Elevated Temperature

“…[5][6][7][8][9][10] Meanwhile, cathode-electrolyte interphase (CEI), a thin layer that usually forms to prevent further electrolyte decomposition analog to solid-electrolyte interphase (SEI) on the anode, becomes excessively thick arising from the side reactions of excess decomposition of conventional solvents at high temperature in the presence of Ni 4+ . [11,12] Such CEI, if dominated by organic components with high impedance, [13] would seriously slow down the ion transportation at the cathode/electrolyte interface, and therefore, lead to capacity decay of the cell. [14][15][16][17] Taking together, simultaneously overcoming the performance degradation and safety issues of NMC811 under elevated temperature becomes very crucial toward practical application, yet remains elusive.…”